added IPAddress construct

Change-Id: Idc57a22b568b33503c78254222d52fbfc19b0b72
diff --git a/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleHostManager.java b/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleHostManager.java
index 3152209..6f0b39e 100644
--- a/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleHostManager.java
+++ b/core/trivial/src/main/java/org/onlab/onos/net/trivial/impl/SimpleHostManager.java
@@ -21,7 +21,7 @@
 import org.onlab.onos.net.host.HostService;
 import org.onlab.onos.net.provider.AbstractProviderRegistry;
 import org.onlab.onos.net.provider.AbstractProviderService;
-import org.onlab.packet.IPv4;
+import org.onlab.packet.IPAddress;
 import org.onlab.packet.MACAddress;
 import org.slf4j.Logger;
 
@@ -96,7 +96,7 @@
     }
 
     @Override
-    public Set<Host> getHostsByIp(IPv4 ip) {
+    public Set<Host> getHostsByIp(IPAddress ip) {
         checkNotNull(ip, "IP address cannot be null");
         return store.getHosts(ip);
     }